Apparatus for investigating earth formations



Sept. 8, 1959 M. MENNECIER APPARATUS FOR INVESTIGATING EARTH FORMATIONSFiled Sept. 23, 1955 4 Sheets-Sheet 1 9 mm mm hmmm mm on mm m Oq mm 5 mmNv p? It INVENTOR. MAURICE MENNECIER o'c'u BY ALINE MENNECIER AEXECUTRIX.

' ATTORNEY.

Sept. 8, 1959 M. MENNECIER APPARATUS FOR INVESTIGATING EARTH F'ORMATIONSFiled Sept. 23, 1955 4 Sheets-Sheet 2 mdE K 4 t a BY EX 57 WW Sept. 8,1959 M. MENNECIER APPARATUS FOR INVESTIGATING EARTH FORMATIONS FiledSept. 25, 1955 4 Sheets-Sheet 3 INVEN TOR. MAURICE MENNECIER DCD BYALINE MENNECIER BY E XEOUT RIX ATTORNEY Sept. 8, 1959 M. MENNECIERAPPARATUS FOR INVESTIGATING EARTH FORMATIONS Filed Sept. 23, 1955 4Sheets-Sheet 4 Maur/ce Mew/7e c/er' fl '62. B Y /4///7e Men/7 6 ever l Il l f EXECUTE/X ATTORNEY United States APPARATUS FOR INVESTIGATING EARTHFORMATIONS Application September 23, 1955, Serial No. 536,251

5 Claims. (Cl. 166-100) This invention relates to apparatus forinvestigating earth formations and, more particularly, pertains to a newand improved earth formation fluid sampler.

One type of fluid sampler proposed heretofore comprises a hollowprojectile disposed within a gun block adapted to be lowered through aborehole to a position adjacent a formation ofinterest. At the desiredlevel, an explosive contained by the gun block is detonated thereby tofire the projectile into the formation. The projectile is connected to areservoir by a flexible tube and has a normally closed front aperturewhich is opened so that formation fluid may pass through the projectileand the flexible tube into the reservoir where it is retained by meansof a check valve. The apparatus may then be raised to the surface wherethe sample can be recovered from the reservoir.

While the just-described arrangement may operate satisfactorily in somecases, the projectile may not al- Ways penetrate far enough into aformation of interest. Thus, the samples may be more representative ofmud or mud filtrate than of any hydrocarbon in the formation. Moreover,in certain formations, such as extremely hard ones, the projectile maynot remain sealed to the wall of the opening it cuts into the formationunder investigation. Thus, drilling mud from the borehole may flow pasttheprojectile and enter its fluid-admitting opening. Obviously, if thisoccurs, the sample may be undesirably contaminated by the drilling mud.

It is an object of the present invention, therefore, to provide a newand improved projectile for an earth formation fluid sampler capable ofpenetrating far into a formation of interest to extract a sample moreaccurately representative of hydrocarbons.

Another object of the present invention is to provide a new and improvedprojectile for an earth formation fluid sampler adapted to obtainsamples of formation fluids with greater reliability than heretoforepossible.

A further object of the present invention is to provide a new andimproved projectile for an earth formation fluid sampler which remainssealed in the opening that it cuts into a formation under investigation.

Yet another object of the present invention is to provide a new andimprovedearth formation fluid sampler capable of extracting a sample offormation fluid with a greater degree of reliability than heretoforepossible.

Still another object of the present invention is to provide a new andimproved earth formation fluid sampler which may be employed to obtain asample of formation fluid free of contamination by drilling mud.

.In accordance with one feature of the present invention, a projectilefor an earth formation fluid sampler comprises a rear portion adapted toeifect an essentially gas-tight, slidable fit in a gun bore and a foreportion that is smaller in cross-section than the rear portion. Aforward section of the fore portion is arranged to be opened to fluidflow and is adapted to be fluidly connected to a sample-conveying tube.

A projectile embodying another aspect of the invention ate-ht icecomprises a body adapted to be impelled toward a selected earthformation and having a forward section adapted to open to fluid flow. Amember is connected to the body and is effectively extensible from theouter surface of the body in a zone behind the forward section, therebyto effect a fluid seal in the selected formation.

According to a further aspect of the present invention, an earthformation fluid sampler comprises a support adapted to be positionedadjacent a selected formation and having a sample-conveying conduit.Means carried by the support defines a gun bore adapted to receive aformation-penetrating projectile, a propellant for impelling theprojectile toward the selected formation, and a tube. One end of thetube is connected to the projectile for entry of a fluid sample and thetube is effectively extensible from the gun bore. The fluid samplerfurther comprises a valve mechanism fluidly connecting the remaining endof the tube and the sample-conveying conduit. The valve mechanism hasone operating condition providing a fluid communication path between thetube and the sample-conveying conduit and is transferable to a secondcondition in which this path is effectively closed. In the secondcondition, the valve mechanism is insentitive to pressure conditions inthe borehole.

The novel features of the present invention are set forth withparticularity in the appended claims. The present invention, both as toits organization and manner of operation, together with further objectsand advantages thereof, may best be understood by reference to thefollowing description taken in connection with the accompanying drawingsin which:

Fig. 1 is a View in longitudinal cross-section of an earth formationfluid sampler incorporating a projectile embodying the presentinvention, the fluid sampler being represented schematically and in onecondition of operation;

Fig. 2 is a fragmentary View of a portion of the projectile representedin Fig. 1, but sholwn outside of the fluid sampler and drawn to anenlarged scale;

Fig. 3 is a view similar to the one shown in Fig. 1, but drawn to asmaller scale and illustrating the fluid sampler in another condition ofoperation; and

Fig. 4 is a view in longitudinal cross-section of an earth formationfluid sampler featuring another aspect of the present invention.

Fig. 5 is a perspective view of an earth formation sampler shown in aborehole traversing a number of earth formations.

In Fig. 5 there is illustrated a sampler unit 10 (excluding theprojectile of the instant invention) constructed in the manner describedin the copending application of R. Q. Fields filed September 23, 1955,bearing Serial No. 536,204 and assigned tothe same assignee as thepresent invention.

Sampler 10 shown in a borehole 13 traversing earth formations 14, 15 and16 containing a drilling fluid 17, such as water base or oil base mud.It is assumed that formation 15 is the one of interest from which afluid sample is to be obtained in a manner to be more apparent from thediscussion to follow.

Sampler 10 comprises a support including a cable head 10a from the lowerend of which a pair of side rails 10b and extend. The lower extremitiesof side rails 10b and 100 are terminated by an end block 10d and aconventional centralizer 10c extends from end block 10d. The centralizermay, for example, include a plurality of bowed springs arranged in theusual manner to center the apparatus in borehole 13. An electric cable10f extends upwardly from cable head 10a and may be employed with awinch (not shown) located at the surface of the earth to lower and raisethe apparatus in the borehole in the customary manner.

Mounted between side rails b and 100 is a first sampler unit comprisedof a gun block 11 positioned below a sample-receiving chamber 12. Asecond, similar sampler unit comprised of a gun block 11a andsamplereceiving chamber 12a is mounted between the side rails below thefirst sampler unit. Of course, although but two sampler units have beenillustrated, obviously, the side rails may be suitably extended toaccommodate any desired number of additional units.

As will be more apparent from the discussion to follow, the gun blocks12, 12a have individual gun bores each adapted to receive a formationpenetrating projectile, a propellant for impelling the projectile towardthe selected formation and an extensible tube having ends connectedbetween the projectile for entry of a fluid sample and the gun bore forreceipt of the sample fluid. In order to actuate or detonate thepropellant in each of the gun bores,

insulated electrical conductors 10g, 1W1, lilk of cable 10f areconnected to suitable igniters, one of the igniters 47 being shown inFigs. 1 and 2. A selector switch 13m is provided for selectivelyconnecting each of the firing circuits to a source of electrical energy,such as a battery 10a which may have in a circuit therewith a rheostat10p and a current indicating meter 10g.

In Fig. l of the drawings there is diagrammatically illustrated aportion of sampler unit 19 including the gun block 11 and thesample-receiving chamber 12. Disposed within a cylindrical, transversebore 18 of gun block 11 is a cylindrical, hollow projectile 19 embodyingthe present invention. The projectile 19 has a rear end portion 20 veryslightly smaller than bore 18 and an O ring 21 seated in an annulargroove 22 provides a fluid seal between end portion Zil and the wall ofbore 18. A tapered section 23 extends between rear portion 20 and aforward portion 24, of a smaller diameter, terminated by a generallyconical formation-penetrating nose 25. By providing a forward portion 24of reduced diameter, increased penetration may be attained.

A cylindrical chamber 26 extends through projectile 19, terminatingshort of nose 25, and a plurality of radial openings 27 extend betweenchamber 26 and the exterior surface of projectile portion 24. Atightly-fitting, slidable ring 28 receives projectile portion 24 therebyto close the outer ends of the openings 27. The ring 28 is held in placeby a sleeve 29 of resilient material, such as rubber, that is tightlyfitted about the ring and the adjacent surfaces of projectile portion 24thereby constituting a retainer as well as a fluid seal for openings 27.

The rear end of projectile portion 20 has a threaded opening 30 whichreceives a portion 31 of a closure 32. Generally stated, the portions ofthe projectile thus far described constitute a cylindrical body adaptedto be impelled toward a selected earth formation in a direction along alongitudinal axis 33 for the body. A portion of the closure 32 is sofabricated as to define an annular recess 34. The recess has a forwardextremity 35 defined by the rear surface of projectile portion 21 in aplane transverse to axis 33 and has a rearward surface 36 of generallyfrusto-conical configuration inclined away from surface 35. An innersection 37 of the recess 34 is slightly enlarged to form a clamp havinga projection 38 for securing an annular sealing member 39 of resilientmaterial in the recess. Thus, an inner portion of the sealing member 39acts as a fluid seal between closure 31, 32 and the rear end ofprojectile portion 20.

The outer configuration of the sealing member 39 conforms essentially tothe shape of recess 34 and it includes a forward portion 40 having aperiphery essentially conforming to the peripheral dimension of section20 of projectile 19. A rearward section 41 of the sealing member 39 isadapted to be substantially conformed to the aforesaid peripheraldimension, but, as shown in Fig. 2, is extensible to a peripheral sizegreater than this peripheral dimension, thereby exposing an innersurface 41. As

will be later seen, this feature permits a good fluid seal to beobtained in the selected formation.

Closure 32 is provided with an axial opening 42 for receiving one end ofa flexible tube 43 to which it is mechanically connected in anappropriate manner. For example, the tube may be silver soldered to thewall of opening 42 and an enlarged head 44 is provided on the tube.Thus, the tube is fluidly sealed to the wall of opening 42, while head44 affords a strong mechanical connection for forward movement withclosure 32. Tube 43 is in fluid communication with chamber 26 and iswound into a plurality of helical turns disposed at the rear end of gunbore 18. The remaining extremity of tube 43 is fluidly connected to aconduit 45 that extends to sample-receiving chamber 12.

A propellant such as an explosive material 46 is disposed at the rearend of gun bore 18 and within the convolutions of tube 43. An electricaligniter 47 extends through a transverse opening 48 in gun block 11 intothe bore 18 where it is in contact with explosive 46.

To condition the fluid sampler for operation, chamber 12 containing onlyair at atmospheric pressure is installed and bullet 19 is positioned inbore 18. Thereafter, the apparatus may be lowered into borehole 13. Whengun block 11 is opposite formation 15, an appropriate electrical circuitis completed between a source of electrical energy (not shown) andigniter 47 thereby to detonate explosive 46 and projectile 19 isimpelled out of gun bore 18 into the formation. Tube 43 uncoils andextends from the gun bore as shown in Fig. 3 thereby permittingprojectile 19 to enter the formation. As the projectile enters, sleeve29 is forced along the surface of projectile section 23, or is ruptured,thus permitting ring 28 to slide to a position adjacent projectilesection 23, unblocking openings 27 to fluid flow. Accordingly, a sampleof formation fluid may flow through openings 27, compartment 26, tube43, conduit 45 and into sample-receiving chamber 12.

By providing a projectile having a forward section 24 of reducedcross-sectional area, greater penetration is secured. Furthermore, byvirtue of the configuration of the outer surfaces of portions 20, 23 and24, an effective seal in the formation is derived. Thus, representativesamples of formation fluids may be obtained.

In addition, since section 41 of sealing ring 39 tends to expand in adirection away from the outer surface of projectile section 20, it formsan effective fluid seal in the opening 49 cut into formation 15 byprojectile 19. Since drilling mud 17 enters opening 49, it is in contactwith inner surface 41 of sealing member 39. Hence, the pressure of thedrilling mud forces the sealing member more tightly against the wall ofopening 49. It is thus apparent that an eflicient fluid seal ismaintained and a sample of formation fluid may be consistently andreliably taken, free of contamination by the drilling mud.

After chamber 12 is filled, unit 10 is drawn upwardly to close a valve(not shown) in the fluid path to the chamber and to break tube 43 asshown in the copending application of Fields, Serial No. 536,204.Thereafter, the unit may be raised to the surface of the earth where thesample is removed.

Although a projectile 19 having a forward section adapted to open tofluid flow in a particular way has been illustrated, obviously othertypes of projectiles may be employed. For example, the projectile may bearranged to open to formation fluids in the manner described in any ofthe following applications which have been assigned to the same assigneeas the present invention: application Serial No. 536,189 of Maurice P.Lebourg and Roger Q. Fields, filed September 23, 1955; applicationSerial No. 536,190 of Andre Blanchard, filed September 23, 1955; andapplication Serial No. 536,115 of Maurice P. Lebourg, filed September23, 1955.

By appropriately selecting the shape and length of pointed nose 25, itcan serve to push aside any mud cake '5 that might be present on thewall of borehole 13. This isespecially useful in arrangements whereinthe very foremost-position of the projectile opens to fluid flow, asdisclosed in the copending applications just mentioned.

If desired, tube 43 may be filled with a relatively incompressibleliquid prior to operation of the fluid sampler. For example, water,alcohol, mercury, or a silicon fluid DC. 200 may be employed. In thisway, a thinner-walled tube can be used while withstanding the force ofthe explosion of explosive 46.

In Fig. .4 the earth formation fluid sampler constructed in accordancewith another aspect of the present invention is shown to comprise asampler unit including a g n block11' and a sample-receiving chamber12'. It

be observed that gun block 11' has its bore 18' inclined downwardly atan angle to a horizontal plane. Thus when the propellant is ignited byconnecting an appropriate source of electric current to igniter leads 50that extend to the surface of the earth, a projectile 51 is impelledtoward the sidewall of borehole 13' and enters at an angle other than90.

As an alternative to the construction shown in Figs. 1 and 3, the foreportion 52 of the projectile may be arranged to minimize compaction ofmaterial in earth formation as disclosed, for example, in theaforementioned copending application of Maurice P. Lebourg and Roger Q.Fields. To this end, the projectile has an opening 53 normally closed bya plug 54 which is driven into a chamber 55 upon impact with formationmaterial. The projectile is thus opened to admit formation fluids whichmay flow through a filter 56 and into a flexible tube 43' that ismechanically connected to a closure 57 for the rear end of bore '18 ingun block 11'.

The fluid path between tube 43 and sample-receiving chamber 12 iscompleted via a conduit 58 in closure 57, a conduit 59 in gun block 11,a flexible tube 60 and a valve chamber 61. In valve chamber 61 there isdisposed an indicator valve comprised of a pivoted vane 62 ofelectrically conductive material having a contact 63 at its free endnormally in engagement with a fixed contact 64. Thus, when fluid flowoccurs, an electrical circuit between a lead 65 that extends to theearths surface and the con ductive material of valve chamber 61 isinterrupted.

Also disposed in valve chamber 61 is an electrically operated valve 66having a bore 67 in which a plunger 68 is slidably positioned. Bore 67is in fluid communication with chamber 12 via a port 69 and with chamber61 via a side port 70. A spring 71 normally holds plunger 68 inengagement with a seat 72, thereby interrupting fluid communicationbetween ports 69 and 70. However, plunger 68 has an extension of magnetmaterial disposed in operative relation with a solenoid coil 73connected to a pair of conductors 74 which extends to the surface of theearth. Accordingly, when the solenoid 73 is energized, the plunger 68 isdrawn downwardly and fluid from the formation may flow into chamber 12'.After the sample is received, the circuit to solenoid 73 is opened andthe valve 66 closes. Thus, in a sequence of operation described above inconnection with Fig. 3, when tube 43 is broken, the sample in chamber12' cannot be contaminated by drilling mud 17.

A sealed chamber 75 houses a pressure-measuring device which may be inthe form of a pressure bomb. This type of pressure gauge comprises apiston 76 slidably movable in fluid sealed relation through an opening77 in a common partition for chambers 12' and 75. The piston is exposedto the pressure in chamber 12' and is biased in a direction opposite tomovement due to pressure by a spring 78. A stylus 79 bears against achart 80 that is driven continuously during operation of the sampler bya clock mechanism 81. Thus, a continuous record of the pressure of fluidin chamber 12' may be obtained during an entire cycle of operation.

If desired, the open end of gun bore 18 may be pro vided with asharpened edge 82 so that the tube 43' may 6 be sheared more easily whenthe sampler unit 10" is drawn upwardly. An additional shear point may beprovided by appropriately weakening a portion of closure 57, for exampleat point 83.

By suitably magnetizing or radioactivating the projectile that issubsequently left in the formation, it may serve as a depth-marker in awell-known manner.

While particular embodiments of the present invention have been shownand described, it is apparent that changes and modifications may be madewithout departing from this invention in its broader aspects and,therefore, the aim in the appended claims is to cover all such changesand modifications as fall within the true spirit and scope of thisinvention.

I claim:

1. In an earth formation fluid sampler, a projectile comprising: ahollow body adapted to be impelled toward and into a selected earthformation in a. direction along an axis for said body and including afluid-admitting forward section of a predetermined cross-sectional areain a plane transverse to said. axis and a rearward section of across-sectional area in a plane transverse to said axis larger than saidpredetermined cross-sectional area and having an annular recess; and anannular sealing member of resilient material secured within said recessand including a forward portion having a periphery essentiallyconforming to the peripheral dimension of said rearward section of saidbody and a rearward section compressible to conform substantially tosaid peripheral dimension, but normally extended to a peripheral sizegreater than said peripheral dimension to elfect a fluid seal in theselected formation.

2. In an earth formation fluid sampler, a projectile comprising: acylindrical body adapted to be impelled toward a selected earthformation in a direction along an axis for said body and having anannular recess, said recess having a forward extremity defining a planetransverse to said axis and a rearward surface of frusto-conicalconfiguration inclined away from said forward surface; and an annularsealing member of resilient material having an inner section securedwithin said recess and an outer section essentially conforming to theconfiguration of said recess, said sealing member further including anouter surface normally of frusto-conical form having a forward sectionsubstantially conforming to a surface defined by the outer extremity ofsaid body and having a rearward section extending from said last-mentionsurface, but said member being deformable to conform substantiallyentirely to said last-mentioned surface.

3. An earth formation fluid sampler comprising: a support adapted to bepositioned adjacent a selected formation and having a sample-conveyingconduit; means carried by said support and defining a gun bore; aformation-penetrating projectile disposed within said gun bore andhaving normally closed sample-admitting opening adapted to be opened tofluid flow after said projectile is imbedded in the selected formation;a propellant disposed within said gun bore for impelling said projectiletoward the selected formation and into the formation so that theprojectile is physically separated from said support; a flexible tubehaving one end connected to said opening of said projectile for entry ofa fluid sample and effectively extensible from said gun bore; arelatively incompressible liquid filling said tube; a fluid conduitconnecting the remaining end of said tube and said sampleconveyingconduit; and a valve mechanism in said fluid conduit.

4. In an earth formation fluid sampler, a projectile comprising: a bodyadapted to be impelled toward and into a selected earth formation andincluding a forward section and a rearward section, said forward sectionhaving a hollow chamber adapted to receive formation fluid, saidrearward section having an annular recess; an annular seal-ing member ofresilient material disposed in said recess having an outer surface offrusto-conical form and an inner surface with a portion thereof with afrusto-conical form, said inner and outer surfaces defining an acuteangle therebetween, the forward portion of said sealing membersubstantially conforming to the surface of said rearward section and therearward portion of said member extending outwardly of saidlast-mentioned surface.

5. In an earth formation fluid sampler, a projectile comprising: a bodyadapted to be impelled toward and into a selected earth formation andincluding a forward section and a rearward section, said forward sectionhaving a hollow chamber adapted to receive formation fluid, saidrearward section having an annular recess; an annular sealing member ofresilient material disposed in said recess having an outer surface offrusto-eonical form and an inner surface with a portion thereof with afrusto-conical form, said inner and outer surfaces defining an acuteangle therebetween, the forward portion of said sealing membersubstantially conforming to the surface of said rearward section and therearward por- 8 tion of said member extending outwardly of saidlastmentioned surface, said resilient member being deformable in saidannular recess to conform substantially entirely to said last-mentionedsurface.

References Cited in the file of this patent UNITED STATES PATENTS2,055,506 Schlurnberger Sept. 29, 1936 2,119,361 Schlumberger May 31,1938 2,303,727 Douglas Dec. 1, 1942 2,381,929 Schlumberger Aug. 14, 19452,441,894 Mennecier May 18, 1948 2,545,306 Pollard Mar. 13, 19512,632,512 Chaney et a1 Mar. 24, 1953 2,674,313 Chambers Apr. 6, 19542,678,804 Lebourg May 18, 1954 2,799,347 Wilcox July 16, 1957 OTHERREFERENCES Ser. No. 271,524, M. Schlurnberger (A.P.C.), published May25, 1943.

4. IN AN EARTH FORMATION FLUID SAMPLER, A PROJECTILE COMPRISING: A BODYADAPTED TO BE IMPELLED TOWARD AND INTO A SELECTED EARTH FORMATION ANDINCLUDING A FORWARD SECTION AND A REARWARD SECTION, SAID FORWARD SECTIONHAVING A HOLLOW CHAMBER ADAPTED TO RECEIVE FORMATION FLUID, SAIDREARWARD SECTION HAVING AN ANNULAR RECESS; AN ANNULAR SEALING MEMBER OFRESILIENT MATERIAL DISPOSED IN SAID RECESS HAVING AN OUTER SURFACE OFFRUSTO-CONICAL FORM AND AN INNER SURFACE WITH A PORTION THEREOF WITH AFURS-